The _______ type in the database/sql package is used to represent a nullable string value.

In the database/sql package of Go, the NullString type is used to represent a nullable string value. This type consists of a string and a boolean flag indicating whether the string is valid (not null) or null. It's commonly used when dealing with nullable columns in a database where a string value might be null. The NullString type provides methods to check if the string is valid and to access its value safely, handling null values gracefully in Go code.